<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <script>
        var a = 1
        var b=6,c=11
        var d
        d=12
        console.log("a=" + a)
        console.log("b=" + b)
        console.log("c=" + c)
        console.log("d=" + d)

    </script>

</body>
</html>